JP3296512B2 - Compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor provided with a rotation speed detecting mechanism.

[0002]

2. Description of the Related Art When a fluid compressor that requires an airtight structure, particularly a refrigerant compressor used for vehicle air conditioning, becomes unable to rotate due to seizure, liquid compression, or the like, power is quickly supplied to the compressor. It is necessary to separate the transmission system from the power source (engine) to prevent damage to the vehicle driving elements. In particular, in a vehicle compressor driven by the same transmission mechanism as other auxiliary equipment such as a water pump and an alternator, the electromagnetic clutch is turned off at the same time as the occurrence of an abnormality, so that the operation of the other devices is not affected. It is important to do so. Therefore, in order to detect such an abnormality, the compressor is conventionally provided with a rotation speed detection mechanism, and when the rotation speed of the compressor becomes a predetermined value or less, the electromagnetic clutch is turned off and the power source is turned off. It is configured to cut off the input of.

[0003] As a known rotation speed detecting mechanism, for example, the invention of a wobble plate type compressor disclosed in Japanese Utility Model Publication No. 3-6878 discloses a leakage flux of an electromagnetic clutch in which races of a main shaft and a bearing are rotated. It has a magnetic circuit formed by passing therethrough, and a detector (magnetic pickup) attached to the housing, and detects a change in magnetic flux by passing a projection provided on the race through the front surface of the detector. ing.

On the other hand, the slide vane type compressor disclosed in Japanese Utility Model Laid-Open Publication No. 58-73991 has a magnetic path formed from an electromagnetic clutch to a drive shaft, a rotor (vane), and an iron core of a detecting portion. The change in magnetic flux is similarly detected by making the detection unit face the end face of the rotor or the vane.

[0005]

When detecting the rotation of various compressors requiring an airtight structure, there are generally problems in how to take out signals, the space for mounting the detector, the size of the output signal, and the like. . In other words, when the detector is mounted in a form penetrating through the body case part, airtightness maintaining means of the mounting part is inevitably attached, and rotation detection is performed by a main shaft part outside the machine or a pulley cooperating with the main shaft. In such a case, it is extremely difficult to secure the mounting position of the detector. Further, if it is attempted to capture a change in the magnetic flux transmitted through the body case outside the machine, it is inevitable that the output signal of the detector is weakened.

[0006] Evaluating from this point of view, each of the above-mentioned conventional rotation speed detection mechanisms is inevitably economically disadvantageous in that it requires airtightness maintaining means, and furthermore, it has a detector which is found in the former configuration. The open air space between the electromagnetic clutches greatly prevents the formation of a closed magnetic circuit, and there is a problem that the detection sensitivity is extremely deteriorated. The present invention has a rotational speed detection mechanism capable of obtaining a sufficient output signal in addition to a simple structure that does not require airtightness, and a technical problem to be solved particularly for providing a compressor suitable for use in vehicle air conditioning. Is what you do.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a plurality of hull members forming an airframe, a fastener for hermetically connecting the hull members, and an electromagnetic clutch inserted and fitted to the airframe. A drive shaft connected to a power source through the movable shaft, and a movable member cooperating with the drive shaft, wherein the compressor is configured to compress the fluid by the operation of the movable member. embedded permanent magnet rotation locus of the magnetic pole is close to the fastener, the said originating from the permanent magnet with causing a periodic change in the magnetic flux which passes through the fastener, machine the outer portion of the head of the fastener A new configuration is adopted in which the change in magnetic flux is detected by a detector mounted in a form surrounding the compressor, and the rotation speed of the compressor is detected based on the detection result.

In a preferred aspect of the present invention, the permanent magnet is embedded so as to protrude from the outer peripheral surface of the movable member .

[0009]

According to the present invention, the permanent magnet on the movable member that rotates together with the drive shaft intermittently faces the fastener, so that the magnetic flux emitted from the magnetic pole of the permanent magnet and transmitted through the fastener changes its period. Occurs, and the amount of change is much larger than the above-described method using the magnetic flux leakage of the electromagnetic clutch,
The induced voltage (output signal) also increases proportionally.

[0010] Then, by the disposing the easy <br/> disjoint detector head portion of the fastener which is exposed to the outside, exactly it is possible to capture the magnetic flux changes at a very high sensitivity, An abnormal rotation of the compressor can be detected without error.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the figure, a front housing 2 is connected to a front end of a cylinder block 1 which is a main body of the compressor, and a rear housing 3 having a suction chamber 3a and a discharge chamber 3b is connected to a rear end of the cylinder block 1 via a valve plate 4. Have been. A crank chamber 5 formed in the front housing 2 is provided with an electromagnetic clutch 6
The drive shaft 7 interlockingly connected through the shaft is inserted, and the drive shaft 7 is rotatably supported by the cylinder block 1 and the front housing 2. A rotary base 8 is fixed on a drive shaft 7 of the crank chamber 5, and a long hole 9 a is formed at a tip end of a support arm 9 extending to a rear surface side of the rotary base 8, and the long hole 9 a A swash plate 11 is slidably fitted with a pin 10 and a rotary swash plate 11 is connected to the pin 10 so as to be tiltable.

That is, the sleeve 12 is loosely fitted on the drive shaft 7 adjacent to the rear end of the rotating base 8.
The pivot shafts 12a projecting from the left and right sides of the pivot swash plate 11 are fitted into engagement holes (not shown) of the rotary swash plate 11, and the rotary swash plate 11
It is supported so that it can tilt around 2a. A swinging plate 13 is supported at the rear end side of the rotating swash plate 11 so as to be relatively rotatable, and a guide portion 13 a provided on an outer edge portion is provided with a through bolt 14.
The piston 16 in the plurality of bores 15 arranged in parallel with the cylinder block 1 and the rocking plate 13 are connected by a connecting rod 17. Therefore, the rotational movement of the drive shaft 7 is converted into the forward and backward swing of the swinging plate 13 via the rotating swash plate 11, and the piston 16 is directly moved in the bore 15 to be sucked from the suction chamber 3 a into the bore 15. The discharged refrigerant gas is discharged into the discharge chamber 3b while being compressed.

The electromagnetic clutch 6 includes a front housing 2
A rotor 61 rotatably supported by the boss portion of the rotor 61 and connected to the engine via a belt, a stator 63 housed and fixed in an annular groove of the rotor 61 and having a built-in electromagnetic coil 62, and transmission of the rotor 61 A disk-shaped armature 64 opposed to the friction surface;
And a hub 66 coupled to the drive shaft 7 via the main shaft 5.

The rotating base 8 (movable member according to the present invention)
Four permanent magnets 20 are embedded and fixed equally in the disk-shaped outer peripheral portion, and the rotation locus of the magnetic pole (outer end) 20a of the permanent magnet 20 protruding from the outer peripheral surface is determined by the through bolt 14 (The fastener in the present invention), and a clear periodic change occurs in the magnetic flux emitted from the magnetic pole 20a and transmitted through the through bolt 14 intermittently facing with the rotation of the rotating base 8. It has been made like that. A detector (pickup coil) 18 fixed to a washer 19 is arranged on the head of the through bolt 14 exposed outside the machine in a form surrounding the head.

This embodiment is configured as described above.
When the electromagnetic clutch 6 is turned on and the drive shaft 7 is rotated by the input from the power source, the rotational movement of the rotating base 8 and the rotating swash plate 11 is converted into forward and backward swinging of the swinging plate 13 and the piston 16 is bored. The compression work is started by reciprocating in the inside 15. At this time, the rotating base 8 that rotates together with the drive shaft 7
Since the upper permanent magnet 20 intermittently faces the through bolt 14, the magnetic flux emitted from the magnetic pole 20a of the permanent magnet 20 and transmitted through the through bolt 14 undergoes a clear periodic change. Detector 1 attached to the head of through bolt 14
8 generates a voltage pulse based on the magnetic flux change,
By calculating the number of pulses, the number of rotations of the compressor can be accurately detected. Of course, when an abnormality such as an extreme decrease or interruption of the pulse number occurs, the clutch mechanism (the electromagnetic clutch 6 in this embodiment) is immediately turned off to prevent damage to the compressor and other auxiliary equipment. It goes without saying that this is done.

When the permanent magnet 20 is completely buried in the rotating body 8 made of a ferromagnetic material (iron-based metal), the magnetic flux emitted from the magnetic pole 20a is conducted to the rotating body 8 and contributes to detection. In this case, it is preferable that the rotating base 8 is formed of a non-magnetic material, or at least the peripheral region of the permanent magnet 20 is surrounded by the non-magnetic material.

Although the above embodiment has been described with respect to the oscillating plate type compressor, for example, a permanent magnet is buried in the maximum sloping peripheral surface of a swash plate used in a swash plate type compressor, and its magnetic pole is passed through. A movable member cooperating with a drive shaft, which can face a bolt and which can make a permanent magnet buried in the movable member close to a fastener extending in the machine. Therefore, the present invention can be applied to a compressor of any specification.

[0018]

As described in detail above, the present invention has the configuration described in the claims, and therefore has the following excellent effects. (1) The intermittent facing between the fasteners of the body and the rotating permanent magnets causes a periodic change in the magnetic flux passing through the fasteners, so that the external arrangement of the detector using the exposed portions of the fasteners is reduced. As a result, the structure can be greatly simplified along with the simplification of the mounting, and more specifically, the case member and the iron core for ensuring the airtightness can be omitted altogether.

(2) Since the change in magnetic flux is generated at the facing portion between the permanent magnet and the fastener which is not hindered by the case member of the detector, the facing distance is set as small as possible, and the detection sensitivity is markedly improved. And can be improved. (3) Since the detector is disposed on the head of the bolt , the connection of the body and the mounting of the detector can be achieved at the same time.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a compressor according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional side view showing a movable member.

[Explanation of symbols]

1 is a cylinder block, 2 is a front housing, 3 is a rear housing, 7 is a drive shaft, 8 is a rotating base, 14 is a through bolt, 18 is a detector, and 20 is a permanent magnet.

Claims (2)

(57) [Claims] A plurality of frame members forming a body, a fastener for hermetically connecting the frame members, a drive shaft inserted into the body and connected to a power source via a clutch mechanism; A movable member that cooperates with the drive shaft, wherein the compressor is configured to compress the fluid by the operation of the movable member. in proximity to the fastener, originating from the permanent magnet with causing a periodic change in the magnetic flux which passes through the fastener, is mounted in a form surrounding the aircraft outer portion of the head of the fastener
Compressor for detecting a magnetic flux change, characterized by being configured to detect the rotational speed of the compressor based on the detection result by comprising detector. 2. The compressor according to claim 1, wherein said permanent magnet is embedded so as to protrude from an outer peripheral surface of said movable member.